Do you need a command card in addition to the air sortie card to activate a plane.

No. If you want to just play an Air Sortie card, you can, but you won't draw a new card (since you didn't play one from your hand) and you will only be able to activate your Plane. Also, if your opponent has a Counter Attack, he can use it to counter your Air Sortie.

If you play Air Sortie with a section card (or certain Tactic cards) then you can order other units as well, and your opponent would only be able to counter the section (or Tactic) card. In either case, if you play an Air Sortie card, you don't have to roll for Air Check.

My pleasure. Have fun with the Air Pack added in! I know that some people don't like the Air Rules as they are written but I really like them; they add an exciting new element to think about and watch out for. I always enjoy when they are added into the game.